Functionally graded variable entropy alloys with resistance to hydrogen induced cracking

Abstract

The disclosure provides for a layered metal with resistance to hydrogen induced cracking and method of production thereof, comprising a core metal alloy and a skin metal alloy. The core metal alloy comprises twinned boundaries. The core metal alloy has undergone plastic deformation and a heat treatment. The core metal alloy comprises nickel and cobalt. The skin metal alloy is disposed on the core metal alloy, wherein the skin metal alloy comprises an entropy greater than the core metal alloy. The core metal alloy comprises a greater density of twinned boundaries than the skin metal alloy. The skin metal alloy comprises a stacking fault energy of at least about 50 mJ/m 2 , and the skin metal alloy comprises iron, aluminum, and boron.

What is claimed is: 
     
       1. A layered metal with resistance to hydrogen induced cracking, comprising:
 a core metal alloy, wherein the core metal alloy comprises twinned boundaries, wherein the core metal alloy has undergone plastic deformation and a heat treatment; and 
 a skin metal alloy disposed on the core metal alloy, wherein the skin metal alloy comprises an entropy greater than the core metal alloy, wherein the core metal alloy comprises a greater density of twinned boundaries than the skin metal alloy. 
 
     
     
       2. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy comprises nickel, chromium, and cobalt in approximately equimolar amounts. 
     
     
       3. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy comprises nickel, cobalt, and vanadium in approximately equimolar amounts. 
     
     
       4. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the twinned boundaries of the core metal alloy are disposed in a first portion of the core metal alloy, wherein a second portion of the core metal alloy is unaffected by a surface treatment and does not comprise the twinned boundaries. 
     
     
       5. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy comprises iron, aluminum, and boron each present in an amount of about 0.5 wt. % or less. 
     
     
       6. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy is a solution strengthened Ni-base superalloy. 
     
     
       7. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy is a precipitation hardened Ni-base superalloy. 
     
     
       8. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy comprises a stacking fault energy of less than or equal to about 25 mJ/m2. 
     
     
       9. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the skin metal alloy comprises nickel, aluminum, cobalt, chromium, and iron each present in an amount greater than 5 wt. %. 
     
     
       10. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the skin metal alloy comprises boron and aluminum such that the combination of the boron and the aluminum induces lattice distortion. 
     
     
       11. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the skin metal alloy comprises a body centered cubic crystalline structure. 
     
     
       12. The layered metal with resistance to hydrogen induced cracking of  claim 11 , wherein the skin metal alloy further comprises a face centered cubic crystalline structure. 
     
     
       13. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the skin metal alloy comprises a face centered cubic crystalline structure, or a body centered cubic crystalline structure. 
     
     
       14. The layered metal with resistance to hydrogen induced cracking of  claim 7 , wherein the core metal alloy comprises nickel in an amount of at least 50 wt. %, boron in an amount of at least 0.05 wt. %, and aluminum in an amount of at least 1.5 wt. %. 
     
     
       15. The layered metal with resistance to hydrogen induced cracking of  claim 6 , wherein the core metal alloy comprises nickel in an amount of at least 57 wt. %. 
     
     
       16. The layered metal with resistance to hydrogen induced cracking of  claim 9 , wherein the skin metal alloy comprises aluminum in an amount of at least 6.6 wt. %. 
     
     
       17. The layered metal with resistance to hydrogen induced cracking of  claim 5 , wherein boron is present in the core metal alloy in a concentration from about 0.01 wt. % to about 0.5 wt. %. 
     
     
       18. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the core metal alloy is a precipitation-hardened or solution-strengthened Ni-base superalloy comprising nickel, chromium, iron, molybdenum, niobium, and tantalum each present in an amount greater than 2 wt. %. 
     
     
       19. The layered metal with resistance to hydrogen induced cracking of  claim 1 , wherein the skin metal alloy has a stacking fault energy of at least 50 mJ/m 2 .